Two more skills that game-based assessments often measure are focus under distraction and switching between rules. These games are our own versions of both task types.
Middle arrow. A row of five arrows appears. Answer the direction of the middle one with the arrow keys. Sometimes the outer arrows point the other way, and that's where slips happen.
Rule switch. A number from 1 to 9 appears with a rule above it: odd or even, or lower or higher than 5. Left means odd or lower; right means even or higher. The rule changes without warning.
Each trial has a time limit, and no answer counts as wrong, so answer every trial even if you have to guess. Your results show where the slips came: on conflicting arrows, or right after a rule change.